• 반도체디스플레이기술학회지
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• 제21권4호
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• pp.99-105
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• 2022

Public attention to the indoor environment of underground subway stations, which is a representative multi-use facility, has been increasing along with the increase in indoor activities. In underground stations, fine iron oxide, which affects the health of users, is generated because of the friction between wheels and rails. Among particulate pollutant reduction technologies, plants have been considered as a non-chemical air purification method, and their effects in reducing certain chemical species have been identified in previous studies. The present study aimed to derive the total quantitative and qualitative reduction effects of a bio-filter system comprising air purifying plants, installed in an underground subway station. The experiment proceeded in two ways. First, PM(particulate matter) reduction effect by vegetation biofilter was monitored with the IAQ(indoor air quality) station. In addition, chemical speciation analysis conducted on the samples collected from the experimental and control areas where plants and irrigation using SEM-EDS(scanning electron microscopy-energy dispersive X-ray spectroscopy). This study confirmed the effect of the vegetation bio-filter system in reducing the accumulation of particulate pollutants and transition and other metals that are harmful to the human body.

• 터널과지하공간
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• 제21권4호
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• pp.297-306
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• 2011

본 연구에서는 지하 압축공기에너지 저장공동 주변 지하수 및 압축공기의 유체유동과 열전달 거동 해석을 위한 다상다성분 열유동 해석 결과를 이용하여 지하 저장공동의 열역학적 에너지수지 분석을 통한 에너지 효율평가를 실시하였다. 복공재인 콘크리트 라이닝이 충분한 기밀성능을 발휘할 경우, 주입 압축과정에서 저장공동으로부터 손실되는 에너지의 대부분은 콘크리트 라이닝 및 주변 암반에의 열전도를 통해 발생함을 확인하였다. 지하 압축공기에너지 저장공동의 에너지 효율은 압축공기 주입온도에 민감한 결과를 보였으며, 주입온도가 주변 암반의 온도에 근사할 경우, 손실된 에너지의 대부분이 토출 팽창과정에서 저장공동으로 유입 회수되는 결과를 보였다. 한편, 콘크리트 라이닝의 열전도특성이 저장공동의 에너지효율에 미치는 영향은 크지 않았다.

• 한국산업보건학회지
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• 제20권4호
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• pp.241-247
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• 2010

Recently, indoor air quality (IAQ) has been one of the major concerns of people. Indoor parking lots are subject to be exposed to high concentrations of air pollutants emitted from vehicles. This study was performed to investigate indoor air quality (IAQ) at indoor parking lots. Sampling sites were selected 5 indoor parking lots. Target indoor air quality parameters include a number of criteria pollutants such PM$_{10}$, CO, CO$_2$, and HCHO. In addition, a variation of IAQ according to ventilation system operating was measured at C site (underground parking lot). In general, all pollutants were maintained below indoor air quality maintenance standards. The indoor air quality at indoor parking lots was affected by the availability of the ventilation facility and their operation frequency. At the underground parking lot (C site) with ventilation system, TVOC concentration according to ventilation system operating were found to be lower operating (488.2 ${\mu}g/m^3$) than non-operating (1,401.2 ${\mu}g/m^3$).

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1993년도 지하공간 건설기술에 관한 서울 심포지움 논문집
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• pp.133-162
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• 1993

The environment of underground spaces might be considered in view of working environment during the construction and living environment after completion of the construction work. For controlling environment of underground space, an appropriate measures have to be taken on the governing factors such as air flow, dust, gases, heat, radiation, noise, illumination and water. The more critical matter, in underground environmental point of view, is underground disasters such as fire, gas explosion and water inrush. This paper presents the general introduction of these factors mentioned above and some outcomes of research works as of now.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.76-81
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• 2007

The shopping center in underground passage increased for efficient space utilization in urban area. This study describes operation characteristics of all air type and hybrid type with local ventilation and fan coil unit fixed to ceiling. In order to compare energy saving, thermal environment and installation space, etc., integrated simulator with heat production and indoor distribution system is designed and constructed. Energy saving of the hybrid system is calculated as over 30% compared to conventional all air type. And also the results showed that humidity decreased about 6%, also indoor thermal distribution is improved as temperature variation of around $1^{\circ}C$.

• 대한전기학회논문지
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• 제41권5호
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• pp.445-458
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• 1992

As one of the forced cooling method of the underground power transmission system, external water cooled system with trough in tunnel was investigated. This study is performed on thermal analysis for a standard condition to determine the cable transmission current of the underground power transmission system about the cooling facility. A parametric study was performed for the inlet water temperatures, flow rates, the inlet air velocities, flow rates and the cooling spans. This study shows that the cable transmission current varies within the allowable limitation in compliance with the variation of inlet water temperatures and flow rates. It exhibits little variations for the most intervals in compliance with the variation of inlet air temperatures and flows. But, the cable transmission current fast reduces for a specified interval and consequently affects the underground transmission system. As a result, when the actual forced cooling system is designed, the design conditions of inlet air have to be considered as the most important parameters in determination of the cable transmission current.

• KEPCO Journal on Electric Power and Energy
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• 제8권2호
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• pp.87-92
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• 2022

Recently, there has been an increasing demand for electric equipment installed on the ground to be installed in an underground space. Accordingly, U-CDS (Underground-Compact Distribution Station) installed in the underground is supplied, and to improve its weak ventilation performance, an Airdam-type structure was applied and the effect was analyzed. As a result, the temperature around the transformer was reduced by up to 9.5 degrees, and the air flow increased by up to 1.17 m/s. Airdam structure can be supplied in the form of various sculptures because it is possible to design freely while maintaining its principle.

• 한국환경보건학회지
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• 제44권3호
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• pp.250-258
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• 2018

Objectives: The study examined indoor air quality during daytime and commute times in underground parking lots in five apartments located in northern Gyeonggi province. Methods: This study examined the temporal characteristics of $PM_{10}$, $CO_2$, CO, HCHO and VOCs in the indoor air quality of the underground parking lots in five apartments. Results: $PM_{10}$ concentration in daytime were ranged from 37.4 to $69.9{\mu}g/m^3$ which complied with the indoor air quality maintenance standard ($200{\mu}g/m^3$) and Gyeonggi province ordinance standard ($180{\mu}g/m^3$). However $PM_{10}$ concentrations in commuting time were in range of $447.3{\sim}944.0{\mu}g/m^3$ that exceeded for both criteria. The $CO_2$, CO and HCHO concentrations complied with the standard. The VOCs indicated high tendency in the order of toluene, xylene, ethylbenzene and benzene. This tendency was more apparent in commuting time than daytime. Conclusion: All indoor parking lots of five apartments were equipped with ventilators. However the most apartment residents did not operate blowers to save electricity and the lack of interest for indoor air quality. In order to improve the indoor air quality of underground parking lots in apartment, operating ventilation system during commuting time is recommended.

• 한국산업융합학회 논문집
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• 제7권3호
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• pp.233-240
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• 2004

This paper presents a feasibility study of a fresh air load reduction system by using an underground double floor space The system was introduced into a real building and was examined by the field measurement Judging from the measurements during three years(1999~2001), the state of the system operation was very stable through this period and it was clear that the system contributes to reduction of energy consumption for air-conditioning. Futhermore, a simulation model used the simple heat diffusion equation Was developed to simulate its thermal characteristics and performances The simulations resulted m air temperature in good agreement with the measurements. Also, from the result of numerical analysis, It is clear that the amount of heat supply by using this system is more than the amount of energy loss to the room above it. Therefore, it is concluded that this systems is very useful and the proposed numerical model can be used for the prediction of system thermal performance.

• 설비공학논문집
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• 제26권3호
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• pp.97-102
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• 2014

For an analysis of the horizontal-type geothermal heat exchanger system, an understanding of the ground temperature distributions is required in order to predict system performance. Because it is difficult to decide on the underground temperature due to the adjustment of its temperature cycle, numerous calculations are required in order to decide on the temperature cycle. In this paper, Buggs formula is utilized to decide a phase shift for outdoor temperature and ground surface temperature, which are obtained from Korea Meteorological Administration. Overall, the underground temperature distribution in the Changwon region is predicted as $10.5^{\circ}C{\sim}20.3^{\circ}C$ at a depth of 3 m.